Organic light-emitting display apparatus

ABSTRACT

An organic light-emitting display apparatus includes a first substrate, a display unit defining an active area on the first substrate and including an insulating layer, a second substrate on the display unit, one or more signal lines outside the active area and on the insulating layer, and a sealant between the first substrate and the second substrate. The sealant bonds the first substrate and the second substrate, and covers at least a portion of the signal lines.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/328,338, filed on Jul. 10, 2014, which claims priority to and thebenefit of Korean Patent Application No. 10-2014-0019222, filed on Feb.19, 2014 in the Korean Intellectual Property Office, the entire contentsof all of which are herein incorporated by reference.

BACKGROUND

1. Field

Aspects of embodiments of the present invention relate to an organiclight-emitting display apparatus.

2. Description of the Related Art

In general, a display apparatus such as an organic light-emittingdisplay apparatus including a thin film transistor (TFT) has beenspotlighted because the display apparatus can be variously applied to amobile display device such as a smartphone, a tablet personal computer(PC), an ultra-thin laptop, a digital camera, a video camera, or apersonal digital assistant (PDA), or to an electric/electronic productsuch as an ultra-thin television (TV).

A gap between a top surface and a bottom surface of an organiclight-emitting display apparatus may be sealed to protect the organiclight-emitting device from external impact or impurities. To this end,the gap between the top surface and the bottom surface may be coatedwith a sealing member, and by hardening the sealing member, the topsurface and the bottom surface are bonded. The lifespan and reliabilityof the display may be affected by the degree of adhesion between the topand bottom surfaces bonded by the sealing member.

SUMMARY

One or more embodiments of the present invention include an organiclight-emitting display apparatus. Additional aspects will be set forthin part in the description that follows and, in part, will be apparentfrom the description, or may be learned by practice of the presentedembodiments.

According to an embodiment of the present invention, an organiclight-emitting display apparatus is provided. The organic light-emittingdisplay apparatus includes a first substrate, a display unit defining anactive area on the first substrate and including an insulating layer, asecond substrate on the display unit, one or more signal lines outsidethe active area and on the insulating layer, and a sealant between thefirst substrate and the second substrate. The sealant bonds the firstsubstrate and the second substrate, and covers at least a portion of thesignal lines.

The display unit may include an organic light-emitting device includinga first electrode, a second electrode, and an intermediate layer betweenthe first electrode and second electrode. The signal lines may beelectrically connected to the second electrode.

The organic light-emitting display apparatus may further include apassivation layer on the insulating layer, and a metal layer on thepassivation layer and electrically connecting the second electrode andthe signal lines.

The metal layer may include a same material as the first electrode.

The organic light-emitting display apparatus may further include apixel-defining layer covering the metal layer and having a contact hole.The second electrode may be on the pixel-defining layer and contact themetal layer through the contact hole.

The pixel-defining layer may be separated from the sealant.

The insulating layer may have a first hole filled with the sealant.

According to another embodiment of the present invention, an organiclight-emitting display apparatus is provided. The organic light-emittingdisplay apparatus includes a first substrate, a display unit defining anactive area on the first substrate and including an insulating layer, asecond substrate on the display unit, one or more signal lines outsidethe active area and on the insulating layer, a pixel-defining layer onthe signal lines and having a second hole, and a sealant between thefirst substrate and the second substrate. The sealant bonds the firstsubstrate and the second substrate, covers at least a portion of thesignal lines and at least a portion of the pixel-defining layer, andcontacts the signal lines through the second hole.

The display unit may include an organic light-emitting device includinga first electrode, a second electrode, and an intermediate layer betweenthe first and second electrodes. The signal lines may be electricallyconnected to the second electrode.

The organic light-emitting display apparatus may further include apassivation layer on the insulating layer, and a metal layer on thepassivation layer and electrically connecting the second electrode andthe signal lines by contacting the signal lines.

The metal layer may include a same material as the first electrode.

The pixel-defining layer may be on the metal layer and have a contacthole. The second electrode may be on the pixel-defining layer andcontact the metal layer through the contact hole.

The sealant may be separated from the second electrode.

The insulating layer may have a first hole filled with the sealant.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will become apparentand more readily appreciated from the following description of exampleembodiments, taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a schematic plan view of a part of an organic light-emittingdisplay apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the organic light-emitting displayapparatus of FIG. 1, taken along a line II-II′ of FIG. 1;

FIG. 3 is a plan view of an area P1 of FIG. 2;

FIG. 4 is a schematic cross-sectional view of a part of an organiclight-emitting display apparatus according to another embodiment of thepresent invention; and

FIG. 5 is a plan view of an area P2 of FIG. 4.

DETAILED DESCRIPTION

As the present invention allows for various changes and numerousembodiments, example embodiments will be illustrated in the drawings anddescribed in detail in the written description. The attached drawingsfor illustrating described embodiments of the present invention areprovided to better understand the present invention and aspects thereof.The present invention may, however, be embodied in many different formsand should not be construed as limited to the embodiments set forthherein.

Hereinafter, the present invention will be described in detail bydescribing example embodiments with reference to the attached drawings.Like reference numerals in the drawings denote like elements, andrepeated descriptions may be omitted. While such terms as “first,”“second,” etc., may be used to describe various components, suchcomponents are not limited to the above terms. The above terms may beused to distinguish one component from another.

An expression used in the singular encompasses the expression of theplural, unless it has a clearly different meaning in the context. In thepresent specification, it is to be understood that terms such as“including”, “having,” and “comprising” are intended to indicate theexistence of features, numbers, steps, actions, components, parts, orcombinations thereof disclosed in the specification, and are notintended to preclude the possibility that one or more other features,numbers, steps, actions, components, parts, or combinations thereof mayexist or may be added.

It will be understood that when a component, such as a layer, a film, aregion, or a plate, is referred to as being “on” another component, thecomponent may be directly on the other component or interveningcomponents may be present. Sizes of components in the drawings may beexaggerated for convenience of explanation, and embodiments of thepresent invention are not limited thereto.

Herein, the use of the term “may,” when describing embodiments of thepresent invention, refers to “one or more embodiments of the presentinvention.” In addition, the use of alternative language, such as “or,”when describing embodiments of the present invention, refers to “one ormore embodiments of the present invention” for each corresponding itemlisted.

FIG. 1 is a schematic plan view of a part of an organic light-emittingdisplay apparatus 1 according to an embodiment of the present invention.FIG. 2 is a cross-sectional view of the organic light-emitting displayapparatus 1 of FIG. 1, taken along a line II-II′ of FIG. 1. FIG. 3 is aplan view of an area P1 of FIG. 2.

Referring to FIGS. 1 and 2, the organic light-emitting display apparatus1 includes a first substrate 101, a display unit 200 defining an activearea AA on the first substrate 101, one or more signal lines 300 (whichmay include, for example, signal lines for supplying signals or powerlines for supplying power) arranged outside the active area AA, a secondsubstrate 102 arranged on the display unit 200, and a sealant 500bonding the first and second substrates 101 and 102.

The first substrate 101 may be a flexible substrate and may be formed ofplastic having high heat resistance and durability. However, the firstsubstrate 101 is not limited thereto and in other embodiments may beformed of various materials such as metal or glass.

The display unit 200 defines the active area AA on the first substrate101. The display unit 200 includes an organic light-emitting diode(OLED) and a thin film transistor (TFT), which are electricallyconnected to each other. Pad units 10 are arranged around the bottom ofthe active area AA and may transmit electrical signals from a powersupply or a signal generator to the active area AA. Hereinafter, thedisplay unit 200 will be further described with reference to FIG. 2.

A buffer layer 103 may be formed on the first substrate 101. The bufferlayer 103 may be formed on an entire surface of the first substrate 101,for example, on both the active area AA and regions surrounding theactive area AA. The buffer layer 103 reduces or prevents penetration ofimpurities into the first substrate 101 and provides a flat surface to atop surface of the first substrate 101. The buffer layer 103 may beformed of various types of materials.

One or more insulating layers 20 may be formed on the first substrate101. The insulating layers 20 may include a gate insulating layer 203and an interlayer insulating layer 205.

The TFT may be formed on the buffer layer 103. The TFT may include anactive layer 202, a gate electrode 204, a source electrode 206, and adrain electrode 207.

The active layer 202 may be formed of an inorganic semiconductor such asamorphous silicon and polysilicon, an organic semiconductor, or acompound semiconductor. The active layer 202 includes a source area, adrain area, and a channel area.

The gate insulating layer 203 is formed on the active layer 202. Thegate insulating layer 203 may be formed to correspond to the entiresurface of the first substrate 101. For example, the gate insulatinglayer 203 may be formed to correspond to both the active area AA and theregions surrounding the active area AA disposed on the first substrate101. The gate insulating layer 203 insulates the gate electrode 204 fromthe active layer 202. The gate insulating layer 203 may be formed oforganic materials or inorganic materials such as silicon nitride (SiNx)and silicon dioxide (SiO₂).

The gate electrode 204 is formed on the gate insulating layer 203. Thegate electrode 204 may contain one or more materials such as gold (Au),silver (Ag), copper (Cu), nickel (Ni), platinum (Pt), palladium (Pd),aluminum (Al), molybdenum (Mo), or alloys such as an Al—Nd (neodymium)alloy or a Mo—W (tungsten) alloy. However, materials included in thegate electrode 204 are not limited thereto, and in other embodiments,the gate electrode 204 may be formed of one or more of various types ofmaterials, depending on a structure of the gate electrode 204.

The interlayer insulating layer 205 is formed on the gate electrode 204.The interlayer insulating layer 205 may be formed to correspond to theentire surface of the first substrate 101. For example, the interlayerinsulating layer 205 may be formed to correspond to the active area AAand the regions surrounding the active area AA.

The interlayer insulating layer 205 is arranged between the gateelectrode 204 and the source electrode 206 and between the gateelectrode 204 and the drain electrode 207 to insulate the gate electrode204 from the source and drain electrodes 206 and 207. The interlayerinsulating layer 205 may be formed of inorganic materials such as SiNxand SiO₂.

The signal lines 300 may be formed on the interlayer insulating layer205. The signal lines 300 may be arranged outside the active area AA.The signal lines 300 may be electrically connected to a second electrode215 and provide power to the second electrode 215. For example, thesignal lines 300 may be a cathode power line (ELVSS). When the signallines 300 are a cathode power line (ELVSS), the cathode power line(ELVSS) may be connected to cathode power having a voltage that is lowerthan a common power supply voltage, for example, the cathode power mayhave a ground voltage or a negative voltage. The signal lines 300 may beformed of the same material and formed through the same process as thesource electrode 206 or the drain electrode 207.

One or more first holes H1 may be formed in the insulating layer 20. Thefirst holes H1 may be arranged outside the active area AA. There may bea plurality of first holes H1. As the first holes H1 may be formed inthe insulating layer 20 and the sealant 500 may be formed on theinsulating layer 20 by filling the first holes H1, contact area of thesealant 500 may be increased. Accordingly, the adhesion of the firstsubstrate 101 and the second substrate 102 may be improved.

The source electrode 206 and the drain electrode 207 are formed on theinterlayer insulating layer 205. In particular, the interlayerinsulating layer 205 and the gate insulating layer 203 are formed (forexample, with contact holes) to expose the source area and the drainarea of the active layer 202, and the source electrode 206 and the drainelectrode 207 are formed to contact the exposed source area and drainarea, respectively, of the active layer 202.

FIG. 2 shows a top-gate-type TFT that sequentially includes the activelayer 202, the gate electrode 204, the source electrode 206, and thedrain electrode 207. However, the present invention is not limitedthereto, and in other embodiments, the gate electrode 204 may bearranged under the active layer 202.

The TFT is electrically connected to the OLED to operate the OLED, andis covered and protected by a passivation layer 208. The passivationlayer 208 may include an inorganic insulating layer and/or an organicinsulating layer. The passivation layer 208 may cover a portion of thesignal lines 300.

A metal layer 400 may be formed on the passivation layer 208 and maycontact the signal lines 300. Since the metal layer 400 contacts thesignal lines 300, the second electrode 215 and the signal lines 300 maybe electrically connected. The metal layer 400 may be formed of the samematerial as and formed through the same process as a first electrode211.

The OLED is formed on the passivation layer 208. The OLED may includethe first electrode 211, an intermediate layer 214, and the secondelectrode 215.

The first electrode 211 is formed on the passivation layer 208. Infurther detail, the passivation layer 208 may be formed (for example,with a contact hole) to expose a set or predetermined portion of thedrain electrode 207 in order not to cover an entire portion thereof, andthe first electrode 211 may be formed to be connected to the exposedportion of the drain electrode 207. In the embodiment of FIG. 2, thefirst electrode 211 may be a reflective electrode. The second electrode215 may be arranged to face the first electrode 211 and may be atransparent or translucent electrode. Therefore, the second electrode215 may transmit light that is emitted from an organic emission layerincluded in the intermediate layer 214. That is, the light emitted fromthe organic emission layer is directly reflected or is reflected by thefirst electrode 211 formed as a reflective electrode, and then may beemitted to the second electrode 215.

However, the organic light-emitting display apparatus 1 in the presentinvention is not limited to a top emission type and, in otherembodiments, may be a bottom emission type in which the light emittedfrom the organic emission layer is emitted to the first substrate 101.In this case, the first electrode 211 may be formed as a transparent ortranslucent electrode, and the second electrode 215 may be formed as areflective electrode. In still other embodiments, the organiclight-emitting display apparatus 1 may be a dual emission type in whichthe light is emitted to top and bottom surfaces of the organiclight-emitting display apparatus 1.

A pixel-defining layer 213 is formed of an insulating material on thefirst electrode 211. The pixel-defining layer 213 may be formed on thesignal lines 300 and may cover the metal layer 400. In thepixel-defining layer 213, a contact hole H0 (or plurality of contactholes) may be formed. The second electrode 215 is formed on thepixel-defining layer 213 and may contact the metal layer 400 through thecontact hole H0. The second electrode 215 may be electrically connectedto the signal lines 300 through the metal layer 400.

The pixel-defining layer 213 exposes a set or predetermined portion ofthe first electrode 211, and the intermediate layer 214 is disposed onthe exposed portion of the first electrode 211. The intermediate layer214 includes the organic emission layer. The intermediate layer 214 mayfurther include at least one of a hole injection layer (HIL), a holetransport layer, an electron transport layer, and an electron injectionlayer. However, the present invention is not limited thereto, and inother embodiments, the intermediate layer 214 may further includevarious functional layers.

The second substrate 102 is arranged on the second electrode 215. Thesecond electrode 215 may be a flexible substrate and may be formed ofplastic having high heat resistance and durability. However, the secondelectrode 215 is not limited thereto, and in other embodiments may beformed of various materials such as metal or glass.

The sealant 500 is disposed between the first and second substrates 101and 102 to bond the substrates. The sealant 500 may be formed outsidethe active area AA. The sealant 500 may include frit. The sealant 500may function as a main barrier that reduces or prevents organicmaterials of the display unit 200 from being deformed due to impuritiessuch as oxygen and moisture from outside.

The sealant 500 may be formed on the insulating layer 20. The sealant500 may be formed by filling the first holes H1 formed in the insulatinglayer 20. Accordingly, the adhesion of the first substrate 101 and thesecond substrate 102 may be improved.

The sealant 500 may cover at least some portion of the signal lines 300.Accordingly, an area where the sealant 500 is formed is increased to anarea where the signal lines 300 are formed. Therefore, the adhesion ofthe first substrate 101 and the second substrate 102 may be improved. Ifthe sealant 500 is formed on the pixel-defining layer 213, the adhesionof the sealant 500 and the pixel-defining layer 213 may not be strongenough, and thus, the sealant 500 may separate from the pixel-defininglayer 213. Accordingly, the sealant 500 may be formed to be separatefrom the pixel-defining layer 213 (such as being separated from thepixel-defining layer 213 by a set or predetermined distance).

Hereinafter, the area where the sealant 500 is formed will be describedin further detail with reference to FIG. 3.

Referring to FIG. 3, the sealant 500 is formed by covering at least someportion of the signal lines 300. Some portion of the signal lines 300contacts the metal layer 400. The metal layer 400 is covered with thepixel-defining layer 213. As the sealant 500 is formed by covering atleast some portion of the signal lines 300, the area where the sealant500 is formed is increased. Thus, the adhesion of the first and secondsubstrates 101 and 102 is improved, and the reliability of the organiclight-emitting display apparatus 1 is improved. As the sealant 500 isseparate from the pixel-defining layer 213 (for example, the sealant 500may be separated from the pixel-defining layer 213 by a set orpredetermined distance D1), contact defects that occur when the sealant500 is formed on the pixel-defining layer 213 may be prevented.

FIG. 4 is a schematic cross-sectional view of a part of an organiclight-emitting display apparatus according to another embodiment of thepresent invention. FIG. 5 is a plan view of an area P2 of FIG. 4.

The embodiment of FIGS. 4 and 5 will be described in comparison with theembodiment of FIGS. 2 and 3. Like reference numerals in the drawingsdenote like elements, and repeated descriptions may be omitted.

Referring to FIG. 4, the organic light-emitting display apparatusincludes a first substrate 101, a display unit 2200 that defines anactive area AA on the first substrate 101, one or more signal lines 300that are formed outside the active area AA, a second substrate 102 thatis arranged on the display unit 2200, and a sealant 2500 that bonds thefirst substrate 101 and the second substrate 102.

A pixel-defining layer 2213 is formed of an insulating material on afirst electrode 211. The pixel-defining layer 2213 is also formed on ametal layer 400. A contact hole H0 (or plurality of contact holes) isformed in the pixel-defining layer 2213. A second electrode 215 isformed on the pixel-defining layer 2213 and may contact the metal layer400 through the contact hole H0. The second electrode 215 may beelectrically connected to the signal lines 300 through the metal layer400.

A second hole H2 (or plurality of second holes) may be formed in thepixel-defining layer 2213 corresponding to the signal lines 300.Accordingly, some portion of the signal lines 300 may be exposed.

The sealant 2500 covers at least some portion of the signal lines 300.Thus, an area where the sealant 2500 is formed is increased by an areawhere this portion of the signal lines 300 is formed. Therefore, theadhesion of the first substrate 101 and the second substrate 102 may beimproved. Furthermore, the sealant 2500 may be formed on thepixel-defining layer 2213. Through the second hole H2, the sealant 2500and the signal lines 300 may further contact each other. Thus, althoughthe adhesion of the sealant 2500 and the pixel-defining layer 2213 maynot be strong enough, the area where the sealant 2500 is formed may beincreased by a portion of an area where the pixel-defining layer 2213 isformed. Accordingly, the adhesion of the first substrate 101 and thesecond substrate 102 may be improved. The sealant 2500 may be separatefrom the second electrode 215 in order to prevent damage to the secondelectrode 215.

Hereinafter, the area where the sealant 2500 is formed will be describedin further detail with reference to FIG. 5.

Referring to FIG. 5, the sealant 2500 is formed by covering at leastsome portion of the signal lines 300. Some portion of the signal lines300 contacts the metal layer 400. The pixel-defining layer 2213 isformed on the metal layer 400, and the second hole H2 is formed in thepixel-defining layer 2213 (for example, corresponding to the signallines 300). Therefore, the sealant 2500 may contact the signal lines 300through the second hole H2. Accordingly, the area where the sealant 2500is formed may be increased by a portion of the pixel-defining layer2213.

As the area where the sealant 2500 is formed is increased, the adhesionof the first and second substrates 101 and 102 may be improved, andthus, the reliability of the organic light-emitting display apparatusmay be improved. The sealant 2500 may be separate from the secondelectrode 215 by a set or predetermined distance D2. As the sealant 2500is separate from the second electrode 215, damage to the secondelectrode 215, which occurs when the sealant 2500 contacts the secondelectrode 215, may be prevented.

As described above, according to the one or more of the aboveembodiments of the present invention, the lifespan and reliability of anorganic light-emitting display apparatus may be improved by improvingthe adhesion of top and bottom substrates, namely, the first and secondsubstrates 101 and 102, of the organic light-emitting display apparatus.

It should be understood that the exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould be considered as generally available for other similar featuresor aspects in other embodiments.

While one or more embodiments of the present invention have beendescribed with reference to the figures, it will be understood by thoseof ordinary skill in the art that various changes in form and detailsmay be made therein without departing from the spirit and scope of thepresent invention as defined by the following claims, and equivalentsthereof.

What is claimed is:
 1. An organic light-emitting display apparatuscomprising: a first substrate; a display unit defining an active area onthe first substrate and comprising a thin film transistor in the activearea, the thin film transistor comprising an active layer, a gateelectrode, a source electrode, and a drain electrode; an interlayerinsulating layer between the gate electrode and the source and drainelectrodes; a second substrate on the display unit; a cathode power lineoutside the active area and on the interlayer insulating layer, thecathode power line being between the interlayer insulating layer and thesecond substrate; and a sealant between the first substrate and thesecond substrate and bonding the first substrate and the secondsubstrate, wherein the interlayer insulating layer defines at least twofirst holes outside the active area, and the at least two first holesare filled with the sealant.
 2. The organic light-emitting displayapparatus of claim 1, wherein the display unit further comprises anorganic light-emitting device comprising a first electrode, a secondelectrode, and an intermediate layer between the first electrode and thesecond electrode, and wherein the cathode power line is electricallyconnected to the second electrode.
 3. The organic light-emitting displayapparatus of claim 2, wherein the thin film transistor is electricallyconnected to the first electrode, the cathode power line comprises asame material as the source electrode and the drain electrode.
 4. Theorganic light-emitting display apparatus of claim 3, further comprisinga gate insulating layer between the active layer and the gate electrode.5. The organic light-emitting display apparatus of claim 2, wherein thesealant is separated from the second electrode.
 6. The organiclight-emitting display apparatus of claim 2, further comprising: apassivation layer on the interlayer insulating layer; and a metal layeron the passivation layer and electrically connecting the secondelectrode and the cathode power line.
 7. The organic light-emittingdisplay apparatus of claim 6, wherein the passivation layer covers atleast a portion of the cathode power line.
 8. The organic light-emittingdisplay apparatus of claim 7, wherein the passivation layer covers atleast an edge portion of the cathode power line between the cathodepower line and the metal layer.
 9. The organic light-emitting displayapparatus of claim 6, wherein the metal layer comprises a same materialas the first electrode.
 10. The organic light-emitting display apparatusof claim 6, further comprising a pixel-defining layer covering the metallayer and having a contact hole, wherein the second electrode is on thepixel-defining layer and contacts the metal layer through the contacthole.
 11. The organic light-emitting display apparatus of claim 10,wherein the pixel-defining layer is separated from the sealant.
 12. Theorganic light-emitting display apparatus of claim 11, wherein thepixel-defining layer covers at least a portion of the cathode power lineexposed between the sealant and the metal layer.
 13. The organiclight-emitting display apparatus of claim 10, wherein the pixel-defininglayer has a second hole, and the sealant covers at least a portion ofthe pixel-defining layer and contacts the cathode power line through thesecond hole.
 14. The organic light-emitting display apparatus of claim4, wherein the gate insulating layer defines at least two third holesfilled with the sealant, and wherein each of the at least two thirdholes corresponds to each of the at least two first holes.